Liquid crystal display (LCD) has been widely used in modern information equipment due to its thin structure and the attribution of energy saving.
In order to reduce the overall power consumption of the liquid crystal display and increase the contrast, the backlight adjustment technique has been utilized in a liquid crystal display fields. At present, the LCD backlight is usually adjusted using the following backlight adjustment algorithm: a frame of picture is divided into n image blocks, the entire backlight region corresponding to the frame of the picture is also divided into n backlight sub-regions, the backlight brightness to be provided by each backlight sub-region when the frame is displayed is calculated depending on the overall display brightness of the plurality of pixels included in each image block (i.e., the so-called sub-backlight brightness of each backlight, the sub-backlight brightness is usually calculated by adding and averaging the display brightness of the plurality of pixels included in each image block). The sub-backlight brightness is supplied to each of the backlight sub-regions respectively, so as to provide a backlight giving different brightness for different regions when the frame of picture is displayed.
This backlight adjustment algorithm can reduce the overall power consumption of the LCD display, increase the contrast, and reduce influence of mura (a ripple phenomenon, that is, when the LCD display a full black screen, if the above adjustment algorithm is not used to adjust the backlight, then the screen has high brightness and the liquid crystal tends to aggregate in blocks under gravity, resulting in ripple phenomenon) on the screen, and can effectively improve the quality of the product. However, according to such adjustment algorithm, the brighter parts and darker parts in each image block are averaged to give a reduce display brightness of the image block, which leads to overall reduction of the brightness of a frame of picture, especially for such pictures which should have bright sense, the brightness is reduced obviously and thus the display quality is lowered.